1. Field of the Invention
The present invention relates to a frame interpolation device and a frame interpolation method for generating at least one or more generated frames between adjacent frames to reduce the intervals between display frames in the reproduction of a moving image. Specifically, according to the present invention, a first motion vector and a second motion vector are translated to pass through the position of a generated pixel in an interpolated frame, and local areas at four points of the start points and the end points of the translated first and second motion vectors are set to be search areas. Then, the first or second motion vector is identified from the search areas. Accordingly, it is possible to distinguish a covered background area and an uncovered background area with a small processing load, and to reduce the deterioration of a boundary area between a foreground and a background in the covered area and the uncovered area.
2. Description of the Related Art
In recent years, liquid crystal displays and organic EL (Electro-Luminescence) displays have been spreading. In such hold-type displays which continue to display a previous frame until an image is newly written, issues of blurring phenomenon and motion jerkiness arise. The blurring phenomenon occurs when the eyes of an observer follow the motion of a moving object in the display of a moving image. In the motion jerkiness, an unnatural motion occurs in the display of a moving image formed by a small number of frames.
The above-described issues can be addressed by reducing the intervals between display frames. To do so, a new frame should be generated from and interpolated between adjacent frames. As a specific method of generating the interpolated frame, it is possible to obtain the interpolated frame by determining a motion vector in accordance with the block matching method or the like and performing motion compensation.
In this method, however, there is an issue in that the search for the motion vector is prevented in a covered background area and an uncovered background area generated in front and rear of a moving object, and thus that correct interpolation is prevented.
To address this issue, Japanese Unexamined Patent Application Publication No. 2004-128702 discloses, as a frame interpolation method in consideration of the covered background area and the uncovered background area, a frame interpolation method which performs correct frame interpolation even in the covered and uncovered areas. According to the frame interpolation method of this patent application publication, local areas indicated by translated first and second motion vectors are detected as search areas. Then, on the basis of the search areas and by the use of four reference frames, the covered area and the uncovered area are detected, and the motion compensation is performed, to thereby generate an interpolated frame.